Fuse construction



Aug. 15, 1933.. E. v. SUNDT 1,922,642

FUSE CONSTRUGT ION Filed Jan. 20, 1932 Eat/lard k Sandi.

Inven 1'0 r Patented Aug. 15, 1933 Application January 20. 1932; ser a No. 587,779?

6 Claims. @(01. 200-131). I

My inventionrelates to improvements in fuse constructions,and it consists in the combinations, constructions, and arrangements herein described and claimed. p Anobject of myinvention is to.provide a fuse construction which is particularly adapted for use inelectrical circuits normally using less than 2/100ths of an ampere. Y

A further object is to provide a construction of the class described having a fuse element comprising a metal coating disposed on and supported by extremely small fibre of any, suitable insulating material such as, for instance, quartz,

glass, silk or the like. I a further object 1 to provide a fuse construction in which the resistance of the fuse element is reduced to the minimum. 1 r

A further object is to provide a construction of the class described having an extremely short fuse element.

A further object is to provide a construction of the class described having a fuse element which may be melted by the passage of electrical currents having extremely low amperage.

Other objects and advantages will appear in the following specification, and the novel features of'the invention will be particularly pointed out in the appended claims.

My invention is illustrated in the accompanying drawing, forming part of this application, in 'which Figure 1 is a perspective view of the embodiment of my invention,

Figure 2 is a horizontal mid-sectional view of the device shown in Figure 1, and t Figure 3 is a sectional view taken along the line 3-3 of Figure 2.

In carrying out my invention, I provide a tube 1 which may be made of any suitable insulating material having suflicient rigidity such as, for instance, glass, quartz, paper or vulcanized fibre. The tube 1 may be provided at either end with an integral inwardly extending annular flange -2. End cap members 3 may be rigidly secured at either end of the tube 1 by means of a lump of a solder 4 of suflicient size to engage the annular flanges 2 in a manner which may be best understood by referring to Figure 2 of the accom panying drawing. Each of the lumps of solder 4 is provided with an inwardly extending supporting wire 5. The wires 5 are rigidly secured in the solder and extend into the tube in such a manner that their inner endportions 5' are spaced apart from each other. The end portions 5 may, if desired, overlap each other and be rigidlysecured together bymeansof a bead 6 which mayv consist of any suitable dielectric material such as, for instance, glass, resinous compounds, or vitreousmaterial. One of the end portions5 maybe provided with a rigidly 6 attached metal spring member '7 which maybe welded or otherwise secured in position.

In the illustrated form of my invention, one of the wires 5 and the end members? may be connected together by a small filament 8, as shown in Figure 2. .While this filament}; may be made ofany suitable conducting material, I preferably employ a filament consisting of a metal coated fibre which may consist of a strand of quarta'glass, asbestos, silk or other fibrous material coated or impregnated with a metal substance such as, for instance. copper, gold, platinum, or silver. v I I If the, f lament 8 consists of a'mere metal wire, the end portions'Q'and 10 may be either soldered or welded to the rod 5 and the spring member 7. When a metal impregnated filament is employed, the end portions 9 and 10 may be cemented in position by any suitable paste in a manner which is well known in the art. The various elements of my invention may be assembled in the following manner. The lead end wires 5 may be held in their spaced-apart parallel relationship shown in Figure 2 and the g bead 6 may be melted around two wires and permitted to cool. The spring member 7 may be secured to'one of the rods 5 either before or after the rods are connected together. by the head 6. The filament, howevenmust be secured in position after the head 6 is applied to the rods 5 and permitted to cool. One of the cap members 3 may now be provided with a .small amount of soldering material which is heated until melted. The end cap member 3 is then held in an upright position and the tube 1 presed into the cap 3 until the annular flange 2 contacts with the base of the cap 3. Before the solder is allowed to cool the outer ends of one of the rods 5 may be placed into the cooling solder 4. The solder 4 is then allowed to cool and the rods 5 are held in position by reason of their being imbedded in the cool solder. The remaining end cap 3 may now be similarly provided with a small amount of solder and heated. This end cap member is then held in an upright position and the tube 1 is carefully forced into the end cap until its'annular flange 2 contacts with the bottom of the end cap. The tube and the end cap are then retained in an upright position until this solder is cooled. The assembly is now complete. Particular attention is directed to the fact that by reason of the annular flange 2 being imbedded in the solder 4, the entire construction is held in position in a secure manner.

The completed fuse is now ready for use.

I claim: 7

l. A construction of the class describedincluding a rigid tube of insulating material having an integral inwardly extending projection disposed at either end thereof, metal end caps rigidly secured to either end of the tube and fixedly engaging the integral projections, and

a fuse element disposed intermediate of the end cap sections and provided with metalsupporting wires, said wires electrically connecting the fuse element to the end cap members.

2. A construction of the class described in cluding a rigid tube of insulating material having an integral inwardly extending projection disposed ateither end thereof, metal end caps rigidly secured to either end of the tube and fixedly engagingthe integral projections, and a fuse element disposed intermediate of the end cap sections and provided with metal supporting wires, said wires electrically connecting the fuse element to the end cap'members, said supporting wires being connected by an insulating bead intermediate of one of the end cap members and the fuse element.

3. As an article of manufacture, a cylindri-- cal fuseconstruction including a rigid tubular casing of insulating material having annular inwardly extending end portions, metal end cap members being soldered and. each engaging one of the annular end portions, supporting conductor wires rigidly secured to an end cap member and to each other, and a fuse element operatively connected in series with the conductor wires and the metal end cap members.

4. A construction of the class described including a rigid tube, oppositely disposed end cap members fixedly secured to the tube at either end thereof, a fuse element, and inwardly projecting wires rigidly and electrically connected to the end cap members and "being connected in series with the fuse element, said tube having anannular inwardly projecting flange at either end thereof, said end cap members being provided with solder and being secured thereby to the annular flange.

5. As an article of manufacture, a cylindrical fuse construction including a rigid tubular casing of insulating material having annular inwardly extending end portions, metal end cap members each having solder therein uniting the same with one of said"annular end portions, a pair of supporting conductor wires each rigidly secured at one end toan end cap membar, a fuse element operatively .connected in series with the conductor wires and the metal end cap members, and a dielectric member with-, in said casing holding the other [end'sfof said Wires in spaced relation.

' 6. A device of the class described comprising an insulating'tube having inwardly extending portions at the ends thereof, metal caps on the 10 ends of said tubes, solder on the interior of each cap for securing said caps to the respective inwardly extending portions of said, tube, and 'a fuse member having the ends thereofterminating within said tube and ,supported solelyf at said ends by said solder in the respective caps.

EDWARD v. senor. 

